I dont think there is a thread like this here so I guess I'll start one. Post some of your favorite iPhone games that are quality. Sometimes it can be hard to weed out all the other ****ty games in the app store. Ill start:

Keep on mind Im playing on an iPhone for and some games dont support the retina display so some of my screens are blurry.

Flood It 2

Its basically a puzzle game where you have to get all of the squares to be the same color at the end. You just touch the circles at the bottom and it changes the squares at the top left to same color and you pick up more squares. You have so many color changes to win.

Geodefense

Picture says it all. My favorite tower defense game in the App store.

Godfinger

This is the best farming type game(like farmville) in the app store imo. Basically you just farm gold and build more buildings. You get one planet, and you can manipulate it to your pleasing(scorch the land so it looks like a desert, make it lush, move land up and down, create a lake). Its pretty good and supports the iphone 4 retina display as you can see its pretty crisp.

Stick Golf

Basically just a golf game, but highly addicting. Right now it has 8 courses that vary completely with 9 holes a piece. Good fun.

Tilt To Live

This is one of my personal favorite. Basically your the arrow and you need to kill the red dots while not touching any of them. Powerups spawn on the level to kill the dots in various ways. There are 4 different kinds of gameplay. The game also has achievements and weapon unlocks. Also the arrow is controlled by tilting your device. Highly recommended.

Words With Friends

Basically scrabble on the go. You can have 20 simulatneous games at once. People play at their own leisure so you can play one turn today and not get another turn until a day later or so. Who doesnt like scrabble?

Its basically an RTS on the iphone. It has local and internet multiplayer. Basically you start at one planet and have to eliminate the enemy players by capturing his planets. Its just like playing mushroom wars on the PS3. This game is actually on steam too.. see here for video.

Soozis is pretty good, i liked it even though its pretty simple.
Castle of Magic looks a little childish but its another decent platformer.
Chaos Rings is a bit expensive for an iphone game but its a decent jRPG, probably the best on the iphone so far

I dont suspect this thread will get many views but I'll keep posting my favorites for a reference later on...

Plants v Zombies

This one needs no introduction, fun game and perfect for the iPhone. I wish they would update for higher resolution iPhone 4 display though.

Eboy FixPix

This game is pretty cool but wont last very long. Basically all you do is align things on the screen to make the image complete. Art direction is nice but wont last long since there are only 100 puzzles and each puzzle takes like 30 second at most.

PathPix

One of my favorite type puzzle games. Basically there are numbers on squares and you have to connect that number to a square with the same number by using that many squares to get to it. Then the finished product is a pixelated image and it gives a quote. Fun game.

NOVA

The premier first person shooter on the iPhone.

Plunderland

I dont know how to describe this game... its kind of like an action adventure. You go around on a boat battling other ships and shooting up islands. Looks nice, I havent spent a crap load of time with it yet.

Fruit Ninja

Very simple quick fix game. Fruit gets thrown on the screen and you have to "slice" them with your finger before they fall. You also have to avoid bombs being thrown up with the fruit.

This is an interesting game with a some good gameplay. You are given 4 elements at the beginning and then you are supposed to mix the elements to come up with new elements. There are nearly 200 combinations that can be made from beginning at 4 elements.

Archetype

Online Multiplayer FPS shooter, rivals NOVA in graphics.

Solipskier

You draw a path and the skier follows it, make him jump to do tricks... get a high score... another good looking quick fix game.

This is a touch adventure game. You interact with things and people in the game to accomplish your task. For example, the first task is to get out of the room you are locked in. This one has quite a bit of humor, pretty good game too. It is a bit short maybe 3-4 hours if you cant figure things out at the most.

Surprisingly simple game yet gets harder to complete. It's a game where you have to cover objects with rope by rotating the object. There are different types of variations the game has but that's basically what younger supposed to do. Cool game and concept.

Physics based puzzle game. You use asteroids to destroy the humans and their ships. Some other asteroids have gravitational push/pull so you have to use that to destroy a lot of the ships. Simple, short, great looking quick game.

If there was any question about the iPhone's capabilities, this should put them to rest. Holy **** it looks awesome in motion running at 60fps on my 3gs. Ambient occlusion, dynamic lighting, parallax mapping and all sorts of ****. This isn't just more powerful than the old Xbox, it is well beyond it.